There has been a long-existing need in the field of manufacturing for a positive quality control device insuring verified grease application along with means for shutting down a machine or assembly line when the requisite grease charge has not been delivered to such grease fitting. Too frequently existing mechanisms for inserting grease into fittings fail to accomplish their desired task resulting in premature frictional damage to machine parts resulting in breakdowns. Moreover, there is at present no available device for insuring the delivery and monitoring of such highly viscous substances as Number One (1) and Number Two (2) grease.
Such highly viscous grease should be applied on a quality control fail safe basis such that if for some reason the grease charge is not delivered as desired, the machine or assembly line is automatically shut down to minimize or eliminate wear of machine parts, viz., those fittings to which no grease was delivered as desired.
It is also desired that the delivery and monitoring device be simple from a mechanical viewpoint; contain a minimum of moving parts; assure economy of motion and have a long life expectancy prior to necessity for replacement. Replacement, of course, would necessitate shutting down the machine or assembly line which is to be avoided.
A variety of devices can be found in the prior art for dispensation of oily lubricants and many of these are complicated and therefore expensive or require particular geometry and/or electrically complicated monitoring and control systems necessitating wasted motion.
U.S. Pat. No. 5,126,722 issued Jun. 30, 1992 to Peter A. Kamis, is directed to a piston-type point of lubrication magnetic flow indicator providing a barrel interfit with a bushing having a cylinder portion penetrating the barrel coaxially and a magnetic piston which reciprocates closely interfit inside the cylinder portion of the bushing. Lube oil enters an inlet port of the bushing, flows through a check valve into the cylinder portion, and impinges on one end of the magnetic piston. The impinging causes the magnetic piston to move in the cylinder portion uncovering at least one port formed through the cylinder portion which opens the cylinder portion to the barrel, directing flow thereto. The lubricating oil flows through the barrel and out of an aperture formed at a forward end of the barrel to a lubrication point. Movement of the magnetic piston through the cylinder portion triggers a magnetic reed switch mounted on an outside circumference of the barrel and generally overlying the relative axial position of the piston in the cylinder portion. The opening and closing of the reed switch can be electrically monitored by electronic lubrication monitoring systems or controls as are known.
U.S. Pat. No. 4,467,892 issued to David L. Van de Borgert on Aug. 28, 1984, is directed to a microlubrication system to divide and distribute a flow of lubricant automatically to one or more machines needing lubrication. Fail-safe, accurate distribution is said to be provided by diverting flow of lubricant from the distribution system most of the time, allowing lubricant to be distributed only at intervals. When the lubricant is being distributed, it flows at a high enough rate to allow accurate metering and division of flow, but the overall delivery rate is low enough to prevent wasting the lubricant. The system is preferably provided with what is stated to be a fail-safe means to insure lubrication or to shut off the machines to be lubricated in the event lubrications fail and cannot be quickly restored.
U.S. Pat. No. 3,993,165, issued to Erhard Pottrich on Nov. 23, 1976, is directed to a lubricant dosing device for double-action, two-conduit central lubricating systems, wherein a housing has therein two piston chambers, an outlet control chamber, two inlets for a pressurized lubricant, and two outlets for determining dosed amounts of the lubricant. One chamber is for a control piston and the other for a dosing piston; the longitudinal aces of all three chambers preferably pass through corners of an imaginary triangle perpendicular to the main axis of the housing. As a main feature, a reversible closing member is insertable in the control chamber, preferably including at least two communicating spaces, bores or grooves, by the aid of which the predetermined dosed amounts of the lubricant can be discharged, by the reciprocation of the dosing piston, selectively through one outlet of the device, when the closing member is inserted in one operative position, and through both outlets, when the closing member is axially reversed before insertion in the control chamber in another operative position. Preferably the axes of the lubricant outlets also pass through one of the corners of the imaginary triangle.
U.S. Pat. No. 3,381,776 issued to T. J. Gruber, et. al. on May 7, 1968, is directed to a lubrication control system for dispensing a measured amount of lubricant within a predetermined period of time having a lubrication dispensing piston, an electronic timing circuit responsive to the movement of the piston and a warning device controlled by the timing circuit for signalling a failure of the lubricating system to dispense an amount of lubricant within the predetermined time interval.